
diff -r 25af24e1f37b -r 180f1b3508ed src/HOL/Statespace/DistinctTreeProver.thy
--- a/src/HOL/Statespace/DistinctTreeProver.thy	Tue Sep 09 17:51:07 2014 +0200
+++ b/src/HOL/Statespace/DistinctTreeProver.thy	Tue Sep 09 20:51:36 2014 +0200
@@ -18,7 +18,7 @@
 
 subsection {* The Binary Tree *}
 
-datatype 'a tree = Node "'a tree" 'a bool "'a tree" | Tip
+datatype_new 'a tree = Node "'a tree" 'a bool "'a tree" | Tip
 
 
 text {* The boolean flag in the node marks the content of the node as




